The present invention relates to an intraoral sensor designed for use in a filmless radiography system.
Dentists and oral surgeons typically use x-radiation (xe2x80x9cx-raysxe2x80x9d) to obtain images of their patients"" teeth, mouths and gums to aid in diagnosis and treatment. In traditional oral and dental radiography, a cartridge containing a piece of photographic film is placed in the patient""s mouth, for example behind a patient""s tooth, and an x-ray beam is projected through the tooth and onto the film. The film, after being exposed in this manner, is developed in a dark room or a closed processor using special chemicals to obtain a photographic image of the tooth.
More recently, the field of filmless dental radiography has emerged. In filmless dental radiography, an x-ray beam is still projected through the patient""s tooth, but no photographic film is used. Instead, an electronic sensor is placed in the patient""s mouth behind the tooth to be examined. The electronic sensor may include a charge-coupled device (CCD) or any other filmless radiation sensor. The x-rays pass through the tooth and impinge on the electronic sensor, which converts the x-rays into an electrical signal. The electrical signal is transmitted over a wire to a computer, either directly or though a module containing intermediate processing circuitry. The computer then processes the signal to produce an image on an associated output device, such as a monitor or a printer.
Filmless dental radiography offers several advantages over traditional film-based radiography. Most importantly, the electronic sensor is much more sensitive to x-rays than is film, allowing the dosage of x-rays to the patient to be lowered by as much as 90%. Also, the image of the tooth is generated by the computer almost instantaneously, thus eliminating the entire developing process, including the use of potentially harmful chemicals. In addition, because the images are generated electronically, they can be stored electronically in a computer database. Examples of filmless dental radiography systems include those described in U.S. Pat. No. 4,160,997 to Robert Schwartz and U.S. Pat. No. 5,434,418 to David Schick. Filmless dental radiography systems typically utilize a standard desktop computer, such as an IBM or IBM compatible type personal computer.
The present invention provides an intraoral sensor configured to fit comfortably and close to a target area in an intraoral cavity. By providing a comfortable relative to the target area, the sensor is ergonomically improved, in terms of its comfort and feel to a dental patient. Whereas prior sensors had housings that were generally rectangular and flat (particularly in cross section), the sensor of the present invention has a predetermined curvature in any plane through the sensor. Thus, certain surfaces of the sensor have non zero curvatures, as described more fully herein. This makes the sensor more comfortable for a patient in comparison to the prior sensors.
In addition, the preferred configuration of the sensor is designed to allow the sensor to be placed closer to a target area in an oral cavity than prior sensors (i.e. closer to target teeth, gum, etc). Moreover, the sensor is configured so that it can easily be located in a correct position relative to the target area, and when located correctly to properly position its sensing structure for receiving radiant energy. These features are believed to reduce refractive error in the image received by the sensor, thereby improving the image data transmitted by the sensor.
Still further, the preferred configuration of the sensor is relatively thin, which also contributes to the improved ergonomics of the sensor, and enables the sensor to get closer to the target area of an oral cavity, thereby improving the image data transmitted by the sensor.
Further features of the present invention will become apparent from the following detailed description taken with reference to the accompanying drawings.